8100 - Laserfiche WebLink

Home Browse Search

EVALUATION OF A SLOT LIMIT ON THE UPPER NORTH PLATTE RIVER, WYOMING MICHAEL A. SNIGG WYOMING GAME AND FISH DEPARTMENT LARAMIE, WYOMING 82070 ABSTRACT The upper portion of the North Platte River consists of 76 miles of Class I (blue-ribbon water) and 24 miles of Class II water between the Colorado-Wyoming state line and Interstate 80 in southeastern Wyoming. Goals were established for the fishery above Saratoga which would serve to protect wild trout and increase numbers of fish towards larger size groups while maintaining acceptable harvest and catch rates. To meet these goals, a slot limit regulation was implemented in 1982. Fish stocking was discontinued in 1984. The river below Saratoga has continued to be managed under the Basic Yield concept. An evaluation of the effects of the slot limit regulation on trout populations and fishermen use and harvest was conducted in 1986. INTRODUCTION AND BACKGROUND The upper portion of the North Platte River consists of 76 miles of Class I water, which is approximately 18% of the total Blue Ribbon water in the state, and 24 mil es of Cl ass II water between the Co 1 orado-Wyomi ng state 1 i ne and Interstate 80 in southeastern Wyomi ng. The town of Saratoga 1 i es approxi mate 1 y one-half of the way through this area. The upper portion of the river is characterized by narrow canyons with rapids and numerous boulders. As the river proceeds downstream through the Saratoga vall ey, the ri ver begi ns to wi den and riparian vegetation and islands provide additional fish habitat. Near the confl uence of Sage Creek and Interstate 80, the drainage area is much more erodible and the river becomes wider and shallower. Flow fluctuations are high due to the unregulated upstream river. Beginning in 1979, this 55 mile section of river was placed under wild trout management due to high rates of natural reproduction in the river and tributaries upstream from Saratoga. Stocki ng of hatchery trout was di scont i nued. Response of the wild trout population to cessation of stocking resulted in increased numbers and biomass of wild rainbow and brown trout. Because of low return rates to the creel, the stocking of catchable size rainbow was discontinued below Saratoga beginning in 1981. In 1984, fingerling 5